The present invention relates to an adjustment arrangement comprising a rotating input element at which a first torque from a motor arrangement can be inputted into the adjustment arrangement, a rotating output element at which a second torque can be outputted by the adjustment arrangement, and a transmission portion for converting the first torque into the second torque. Further, the present invention relates to a valve control system for controlling the movement of a valve relative to a base portion at a predetermined pivot angle, the valve control device comprising an adjustment arrangement of the aforementioned type.
Adjustment arrangements of the aforementioned type are known in the prior art as electromechanical actuators, and generally use a planetary transmission to convert the relatively rapid rotation of an output shaft of an electric motor into a slower rotation of an output element of the actuator. However, planetary transmissions are relatively expensive and high-maintenance for construction reasons, since they require a number of gear wheels movable on different shafts. Furthermore, the transmission ratio (reduction ratio or multiplication ratio) of planetary transmissions is limited depending on the available installation space. Adjustment arrangements are further known which comprise a worm gearing so as to achieve a relatively high reduction ratio. However, for construction reasons, worm gearings require the mounting of two shafts arranged at an angle to one another, and so in this case too there is an increased complexity of construction and increased installation space requirement.